Circuit breaker mechanism



y 1944- J. M. CUMMING ET AL CIRCUIT BREAKER MECHANISMS Filed April 4, 1942 I5 Sheets-Sheet l I 7 I 2 90 s 1 9mm 1 J 3 5% k. 3 7 0X wnusssas;

137 INVENTORS James M 011172271172 and AZf/Y W Hill. a ATTORN y 23, 1944- J. M. CUMMING ET AL 2,349,650

CIRCUIT BREAKER MECHANISMS Filed April 4, 1942 5 Sheets-Sheet 2 Mb; INVENTORS James M 0212727722; d/70 A/[an W Hill.

y 23, 1944. J. M. CUMMING ETAL 2,349,650

CIRCUIT BREAKER MECHANISMS Filed April 4, 1942 a Sheets-Sheet a WITNESSES: |NVENTOR5 w James M Cumming and Alla/2 W Hill. J

BY Z i I L p I a Z/ ATTORNE Patented May 23, 1944 CIRCUIT BREAKER MECHANISM James M. Cumming, Turtle Creek, and Allan W.

Hill, Wilkinsburg, Pa., assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 4, 1942, Serial No. 437,668

14 Claims.

This invention relates to circuit breakers and more particularly to operating means for operating a circuit breaker.

An object of the invention is the provision of a circuit breaker with a manual closing device which is operable to automatically release the breaker and permit opening thereof in response to predetermined conditions.

Another object of the invention is to. provide an improved manual closing device for a high power circuit breaker which is detachably associated with the breaker operating mechanism.

Another object of the invention is to provide a detachable manual closing device for a high power circuit breaker comprisin a traveling latch releasably engageable with a part movable with the breaker operating mechanism and manually operable to close the breaker.

Another object of the invention is to provide an improved closing device for a circuit breaker comprising a latching mechanism for releasably connecting the closing device to a part movable with the breaker, the latching mechanism being provided with an automatically operable locking device for releasably locking the latching mecha-' prising means for releasably coupling the closing device to the breaker and a trip device mount- I ed on the closing device and operable in response to predetermined circuit conditions to automaticall disconnect the breaker from the closing device.

Another object of the invention is to provide a manual closing device for a circuit breaker comprising latch means for releasabl coupling the closin device to the breaker and a trip device mounted on movable with the closing device, the trip device being automatically operable to release the latch means and thereby uncouple the breaker from the closing device, the trip device also being manuall operable to uncouple the closing device from the breaker.

Another object of the invention is the provision of a circuit breaker with an improved manually operable closing device which is simple, reliable in operation and inexpensive to manufacture.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation together with additional objects and advantages thereof will be best understood from the following detailed description of a single embodiment thereof when read in conjunction with the accompanying drawings, in which:

Figure 1 is an elevational view, partly in section, of a compressed air operated mechanism for a circuit breaker, and a manually operated closing device embodying the principles of the invention.

Fig. 2 is a side elevational view of the mechanism shown in Fig. 1.

Fig. 3 is an enlarged sectional view of the manual closing device, taken substantially on line IIIIII of Fig. 2.

Fig. 4 is a plan view taken on line IV-IV of Fig. 3 showing the manual closing device.

Fig. 5 is a perspective view, partly in section, of the mechanism for latching the manual closing device to the breaker operating mechanism; and,

Fig. 6 is a wirin diagram of the electrical control circuits for the circuit breaker operating mechanism and the manual closing device, the breaker and the operating mechanism being shown schematically.

Referring to Fig. 6 of the drawings, the circuit breaker I shown schematically, may be of any conventional construction and comprises stationary contacts 3 and a movable bridging contact member 4 for cooperating with the contacts 3 to open and close a main circuit indicated by the single line 5. The circuit breaker may be of the multi-pole type in which case a set of contacts 3 and 4 is provided for each pole with the bridging contact members 4 connected together for simultaneous movement in the well known manner. The circuit breaker is biased to open position b means of an accelerating spring 6 and is mechanically connected to the operating mechanism indicated generally at 1 by means of a lever 8 pivoted at 3 on a fixed support. One end of the lever B is pivotally connected to the reaker lift rod in and the other end is pivotally connected to a breaker operating rod H which is connected to the operating mechanism 1.

Referring to Fig. 1, the circuit breaker operating mechanism 1 comprises a main casting ll forming a cylinder l2 in which a piston I 3 is adapted to be operated by compressed air to close the circuit breaker. lhe cylinder is closed at its lower end by a closure member I5 secured thereto. The breaker operating rod I'I extends axially through openings in the castin II, the piston l3 and the closure member I5, and is secured to the piston I3 by means of a shoulder on the rod I! and a nut I9 threaded on to the rod. The operating rod I! is pivotall connected to an operating lever 2| comprising a pair of parallel levers 23 (Fig. 2'), by means of a, pivot pin 25. The operating levers 23 are pivotally connected by a pivot pin 26 to the upper ends of a pair of parallel links 21 which are pivotally mounted by means of a pivot pin 29 on projection 3| f the main casting II. A yoke member 33 secured on the lower end of the operating rod II carries a pin 35 with which a manual closing device, indicated generally at 31, is adapted to cooperate to manually close the breaker.

The free ends of the levers 23 carry a short shaft 39 which rotatably supports a roller III disposed between-the levers. A high speed latching mechanism including a main latch 43 is adapted to engage the roller III to releasably hold the operating lever 23 in closed position thus holding the circuit breaker in closed circuit position. The latch 43 is pivotally supported on a pivot 45 mounted in the main casting II and is biased to latching position againsta stop 47. by means of a spring pressed plunger 49. The plunger 49 is slidably mounted in an opening in a portion of the main casting I I and is biased inwardly by means of a compression spring 51.

The construction of the latch face of the main latch 43 is suchthat this latch, by itself; will not serve to hold the breaker operating lever 2I in closed position. For this reason a trigger latch 53 is provided for engaging and holding the main latch in latching position. The trigger latch 53 is pivotally supported on the main casting by means of a pivot pin 55 and has a latching projection 51 which engages under a tail of the main latch in the latching position of the main latch. The trigger latch is biased to latching position by a compression spring 59. A tail 6| of the trigger latch 53 extends directly over the upper end of a trip rod 53 which forms a part of an electromagnetic trip device 65. In addition to the trip rod 63 the trip'device includes an E-shaped magnet core 61 suitably mounted on the main casting II and having an energizing winding 69 around its center leg. The trip rod 63 is slidable vertically through the center of the core member and has an armature II secured thereto below the core 51. The trip rod 63 and the armature II are biased downwardly by means of a spring 13 disposed between the main casting II and a collar on the trip rod.

Referring to Fig. 6, the winding 69 of the trip device 65 is connected in an energizing circuit extending from an auxiliary source conductor I55, conductor I59, contacts I6I of a conventional fault responsive relay I63, through a conductor I65, winding 63 and through conductors I51 and I85 to the other source conductor I69. The fault relay is adapted to be operated to close the contacts I! upon the occurrence of a predetermined overload condition in the main circuit 5. The energizing winding of the fault relay I 63 is energized by a current transformer I'II which isadapted to be energized by the main circlose the contacts I6I and effect energization of the trip device I55.

When the trip device 65 is energized the armature 'II is attracted upwardly against the core 61 moving the trip rod 63 upwardly therewith. This movement of the trip rod rotates the trigger latch 53 counterclockwise and disengages the tail 5! thereof from the main latch 43, whereupon the accelerating spring 6 (Fig. 6) of the circuit breaker moves the breaker to open circuit position rotating the operating lever 2| counterclockwise to the position shown in Fig. 1. During the initial movement of the operating lever to open position the roller 4| (Fig. 1) cams the main latch 43 counterclockwise, the spring 5I acting to restore the main latch to latching position as soon as the roller clears it. In order to prevent the trigger latch 53 from resuming its latching position before the operating lever 2i has returned to closed position, a U-shaped holding lever I5 is provided, the legs of which are pivoted on the pivot pin 55. The holding lever I5 is biased in a counterclockwise direction by a spring II'seated in a recess in the main casting II and which engages a projection I9 of the holding lever. The free end of the holding lever 1.5 is disposed direct- 1y beneath the end of the operating lever 2I so that the holding lever is held in inoperative position when the operating lever 2| is in closed position. When the operating lever H is released and moves toward open position, the spring 1! rocks the holding lever counterclockwise and the projection I9 thereof engages and holds the trigger latch 53 in unlatched position until the operating lever 2| is returned to closed position.

The circuit breaker is normally closed or automatically reclosed by downward movement of the piston I3 which is efiected by compressed air admitted to the upper end of the cylinder through an inlet passage 8|. The inlet passage 8I is con- "trolled by a main inlet valve indicated generally at 83, and the opening operation of the inlet valve is controlled by a pilot valve which is operated by an electromagnet 81. The main inlet valve and the pilot valve are not shown herein in detail since they form no part of the present invention.

It is thought sufi'icient to state here that the electromagnet 81 may be energized from any suitable source either manually or automatically to cause opening of the pilot valve 85 and admit air under pressure from a reservoir 89 (Fig. 1) to operate the main inlet valve 83. Operation of the main valve 83 admits compressed air through the inlet passage BI to the upper end of the cylinder I2 forcing the piston I3 downwardly and moving the breaker to closed position. As the operating lever 2| arrives at closed position, the roller 4| slips by the main latch 43 which is immediately restored to latching position by the spring 5I. Also as the lever 2| arrives at the closed position, the end thereof engages and rocks the holding lever I5 to its inoperative position which permits the trigger latch 53 to resume its latching position.

The trip device 55, in addition to operating the latching means 4353, also controls a pilot valve 84 which in turn controls the operation of a dump valve (not shown) for dumping pressure air from the upper portion of the cylinder through a large port 86 to atmosphere, upon operation of the trip device 65. This permits the breaker to open quickly without being opposed by pressure air above the piston I3 thus producing the effect of trip free operation. I

The operating mechanism as thus. far described, with the exception of the manual closing device 31, is of the same construction as dis.- closed and claimed in the copending application of J. M. Cumming and R. C. Cunningham, Serial No. 410,686, filed September 13, 1941, and assigned to the assignee of the present invention.

As previously set forth, the manual closing device 3 1 is adapted to be engaged with the pin 35 carried by the yoke member 33 secured to the lower end of the operating rod I1, and manually moved downwardly to close the breaker. The closing device 31 includes a traveling latch comprising a plurality of latch levers 9| pivotally supported on a pivot pin 93 and adapted to be disposed two on one side of the pin 35 and one on the opposite side of said pin when the closing device is set in position to close the breaker. The pivot pin 93 is mounted in a substantially rectangular carriage or frame 95 comprising parallel side members 96 (Fig. 4) joined at the bottom by a plate 98 (Fig. 3) formed integral with, the side members 98. The side members 96 are also joined at each end (Figs. 3 and 4) by cross members "I also formed integral with the side members. Bosses 9,! formed integral with the side members 95 are provided with threaded openings to receive a pair of vertically disposed operating screws 99 rotatably mounted in bearings I-OI extending upwardly from a base casting I03. On the lower end of each of the screws 99 is secured a gear I05 (only one being shown) disposed in housings formed by the casting I I33. A ball thrust bearing III-I is provided between each of the gears I85 and the inside of the casting I03. Each of the gears I05 meshes with a worm I69 secured on a horizontally disposed shaft I II rotatably mounted in bearings in the casting I03. The shaft III- is provided with a squared end II 3 (Figs. 1 and 4) projecting beyond the base housing and which is adapted to receive a hand crank (not shown) so that the shaft III, gears I09 and H and the screws 89 may be manually rotated to effect vertical movement of the frame 35 and the latches 91'.

The latch levers 9| are spring pressed to their latching positions by means of springs I'I5 (Figs. 1. 3 and 4') coiled around plungers II? and disposed between rounded heads I "I 9 of the plungers and the cross members IZI integral with the frame 85. The plungers II"! are slidable in the cross members 121 and their inward movement is limited by cotter pins !23 therein bearing against the outside face of the cross members. The lower ends of the latch levers 9I are connected: by a toggle comprising a bifurcated toggle link I25 (Figs. 3 and 5) and a toggle link I2 1 comprising a pair of links. The bifurcated end of the toggle link l25 straddles the lower end of the single latch lever BI disposed on one side of the pin 35, and is pivotally connected thereto by means of pin I 29. The toggle links I21 are disposed on each side of the toggle link I 25 and are connected thereto by a knee pivot pin I3I. The other ends of the links. I21 are pivotally connected to the lower ends of the other two latch levers 94 by means of a single pin I33 extending through openings in the latch levers SI and in the toggle links I21. The toggle I25I2I is normally overcenter below a line through the centers-of the pins 129 and I33 and thus maintains the latch levers 9! in their latching positions as shown.

The manual closing device 31 is not permanently attached to a single breaker mechanism but may be removably attached to anyone of a number of breakers for the purpose of manually closing them. In order to attach the device 31, the screws 99 are rotated in a direc tion to lower the traveling frame and the latch levers 9| carried thereby. The base I03 of the device is then inserted beneath angle brackets I35 (Fig. 1) secured to a fixed part I 31 of the breaker mechanism structure and so located that the latches 9I will be positioned directly below the pin 35. The screws 99 are now rotated in a direction to raise the traveling latch mechanism in order to engage the latch levers 91 with the pin 35. Since the toggle I25I2'I at this time is overcenter in a position to lock the latches 9 l. in their latching positions, it is necessary to provide means to collapse the toggle over center above the line I29-l33 before the latches 9-! may be engaged with the pin 35.

Referring to Figs. 3, 4 and 5, it may be observed that a pair of toggle'operating levers I39 is pivotally supported on the pin 93 and each of the lovers I39 has its lower end Hi0 disposed in cooperative relation with a projection I 42 on the outer end of each of the toggle links I21. The upper ends of the latches 9| are beveled at I. The upper ends of the toggle operating lever I39 are also beveled as at I45 and extend upwardly a greater distance from the center 93 than do the latches.

As the screws 93 are rotated to raise the travel ing latch mechanism the beveled faces I46 of the operating levers 839 will first engage the pin .5 continued upward travel of the carriage causes the levers I39 to wipe by the pin 35 which results in rocking the levers clockwise (Fig. 3) about the pivot 93. At this movement the lower ends I 20 thereof engage the projections I42 of the toggle links it! rock these links'clockwise. about the pin I33 causing collapse of the -!21. With the toggle in collapsed condition. further upward movement of the traveling latch mechanism 31 brings the beveled faces 14: o the latch levers BI into engagement with the pin 3,5 which causes further separation of the latches. As the upward movement of the mechanism continues the latching ends of the latch levers 9| pass above the pin 35 whereupon the springs i I 5 act to move the latch levers into latching engagement with the pin. The head H9 of the plunger Ii! which is disposed in cooperative relation with right hand latch levers 9i (Figs. 3 and 4) also engages the toggle cneratin, levers 139 and rocks these levers counse to the position in which they appear in Fig. At this time, the lower ends MD of the levers I 39 free the projections I42 on the toggle links I2? whereupon the toggle I25-I2? resumes its overcenter holding position under the combined influence of the springs H5 and of gravity.

The latches 9| are now fully engaged with the pin 35 and locked in this position by means of the toggle I25 I2l. The screws 39 are now rotated in a direction to lower the traveling latch mechanism 31, which draws the breaker operating rod I l downwardly to close the breaker at the same'timc rotates the operat ng lever 21 clockwise to its closed position where it is latched in the previously described manner.

One of the important features of the inven-- tion is the provision of a detachable manual closing means for a circuit breaker where n the breaker is trip free of the manual closing means during the entire length of closing travel.

7 The trip-free device includes an electromagnet I II (Figs. 1, 2, 3, and 6) comprising an E- shaped core member I43, mounted on the under side of the bottom plate 98 of the frame 95 by means of brackets I45 (Fig. 2), and having an energizing coil I41 surrounding the center leg of the core. A movable armature I49 is secured to the lower end of a vertically disposed trip rod II extending through an opening in the core member and an opening in the bottom plate 98. The upper end of the trip rod "H is disposed directly beneath the knee of the toggle I25I21 and has a nut I53 threaded thereon which engages the upper face of the bottom plate 98 to limit the downward movement of the armature.

of'breakers, the winding I41 is provided with a plug-in device I13 (Fig. 6) which may be plugged into a receptacle I15 connected to the control circuit for the particular breaker to be closed. The circuit for energizing the winding I 51 extends from the control source conductor I55, the conductor I51, a conductor I11,.contacts Ilila of the fault relay I53, a conductor I19 to one terminal (not shown) of the rece tacle I15, one side of the plug I13, a conductor ml, the winding I41 of the trip device IN, a conductor I83 to the other side of the plug I13, from the other terminal of the receptacle I15 over a conductor I85 to'the other side I59 of the control source.

When it is desired to manually close a circuit breaker the closing device 31 is coupled thereto in the previously described manner and the plug I13 is inserted into the receptacle I15 of that particular breaker thus connecting the Winding I41 in the control circuit for the breaker being closed. Should an overload of predetermined value or a short circuit occur during the closing movement of the breaker when it is being closed by means of the manual closing device 31, the magnet I II will be immediately energized. Energization of the magnet attracts the armature I 49 and thrusts the rod I5I upwardly forcing the toggle i|21 overcenter in a direction to cause its collapse. When this occurs the upward force of the breaker operating rod I1, occasionedby the breaker accelerating spring 6 which biases the rod I1 upwardly in opening direction. causes the pin to separate the latching ends of the latches 9|, freeing the pin 55 therefrom and permitting the accelerating spring 3 to move the breaker I to open position.

As soon as the magnet MI is deenergized the latch levers 9! are restored to their latching positions by the springs H5, and the weight of the toggle links I25I21 causes the toggle to resume its overcenter holding position. The closing device 31 may be reconnected with the pin 35 in order to again close the breaker. In order to manually disconnect the latches SI from the pin 35, the armature I49 may be manually raised to cause collapse of the toggle I25-I21 and while holding the toggle in collapsed condition, the shaft III may be rotated in a direction to cause the screws 99 to lower the frame 95 thereby disengaging the latch levers 9i from the pin 35.

While the invention has been disclosed in accordance with the provisions of patents statutes, it is to be understood that various changes in the structural details and arrangements of parts thereof may be made without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given the broadest reasonable construction permissible in the light of the prior art.

We claim as our invention:

1; The combination of a circuit breaker, a member movable to close the breaker, power operated means for moving said member to close the breaker, a tripping means efiective to trip the breaker in response to predetermined abnormal conditions while mechanically connected to the power operated means, manually operable means engageable with said member for movin the member to close the breaker, and a trip-free tripping means effective to cause disconnection of the movable member from the manually operable means in response to predetermined abnormal conditions occurring during a closing movement of the manually operable means.

2. The combination of a circuit breaker, a member movable to close the breaker, power operated means for moving said member to close the breaker, manually operable means releasably engageable with the member and operable to move said member to close the breaker, and a trip device movable with the manually operable means and responsive to predetermined abnormal, conditions to cause disengagement of the movable member from the manually operable means.

3. The combination of a circuit breaker, an operating member movable to close the breaker, means comprising a fluid motor for moving said operating member to close the breaker, a trip device operable in response to predetermined overload conditions to cause opening of the breaker, a manually operable closing device operable to move said operating member to close the breaker, and a trip device movable with said manually operable closing device and operable in response to predetermined circuit conditions to cause opening of the breaker irrespective of the closing movement of the manually operable closing device.

4. The combination of a circuit breaker, an operating member movable to close the breaker, means comprising a fluid motor operable to move said operating member to close the breaker, a trip device operable in response to predetermined circuit conditions to cause opening of the breaker, a manually operable closing device including a traveling latch mechanism for releasably connecting said closing device to the operating member, manually operable means for operating the latch mechanism and the operat-- ing member to close the breaker, and a trip device movable with the latch mechanism and operable in response to predetermined circuit conditions for causing said latch mechanism to release the operating member.

5. in a circuit breaker having a latch mounted on a fixed part for holding said circuit breaker in closed position, closing mechanism for said circuit breaker comprising a movable carriage, manually operable means for moving said carriage in a direction to close the breaker, means for coupling the carriage to a part movable with the breaker, and a trip device movable with the carriage and operable to cause opening movement of the breaker irrespective of the closing movement of the carriage.

6. A closing mechanism for a circuit breaker comprising power operated closing means operatively connected at all times with said breaker, a reciprocably movable carriage, manually operable means for moving said carriage, latching mechanism for releasably coupling the carriage to a part movable With the breaker, said carriage being movable in one direction to effect said coupling and movable in another direction to move the breaker to closed position, and a trip device operable in response to predetermined conditions to cause automatic uncoupling of the breaker from said carriage.

7. A closing device for a circuit breaker comprising power operated closing means operatively connected at all times to said breaker, a reciprocably movable carriage, manually operable means for moving said carriage, a plurality of latches pivotally mounted on said carriage for detachably connecting the carriage to a part movable with the breaker, said carriage being movable in one direction to effect said connection and movable in another direction to move the breaker to closed circuit position, and means for restraining the latches in latching position.

8. A closing device for a circuit breaker comprising a movable carriage, manual operating mechanism for moving said carriage in a direction to close the breaker, a plurality of opposing latches on the carriage for releasably connecting said carriage to the breaker, common locking means for looking all of said latches in latching position, and electroresponsive means movable with the carriage and operable in response to predetermined conditions to cause opening movement of the breaker irrespective of the closing movement of the carriage.

9. In an operating mechanism for a circuit breaker, the combination of a part movable to an open position and to a closed position for opening and closing the breaker, power operated closing means operatively connected at all times to said part, a movable carriage, means for coupling said carriage to said part, means for restraining the coupling means in coupling position, manual operating mechanism for moving the carriage in a direction to close the breaker, and a trip device automatically operable during a closing movement of said carriage in response to predetermined conditions for operating the restraining means to cause opening of the breaker.

10. The combination with a circuit breaker, of a main operating device comprising a fluid motor for operating the breaker to closed circuit position, an auxiliary operating device removably attachable to a fixed part and to a part movable with the breaker for manually operating the breaker to closed circuit position, said auxiliary operating device comprising a movable carriage, a plurality of latch members mounted on said carriage and operable to releasably connect the carriage to the part movable with the breaker, and manually operable mechanism for moving the carriage in a direction to move the breaker to closed position to cause closing of the breaker.

11. The combination of a circuit breaker, an operating member movable to close the breaker, power operated means for moving said member to close the breaker, a manually operable closing device including a, traveling carriage, a plurality of latch members pivotally mounted on said carriage for releasably connecting said carriage to the operating member, means comprising a toggle connecting said latch members for restraining said latch members in latching position, and a trip device operable in response to predetermined circuit conditions for operating said togg le to cause opening of the breaker.

12. The combination of a circuit breaker, an operating member movable to close the breaker, a manually operable device including a traveling carriage for moving the operating member to close the breaker, a plurality of latch members biased to latching position for connecting the carriage to the operating member, a toggle for restraining the latch members in latching position, means engageable by the operating member for operating the toggle to effect said connection, manually operable means for moving the carriage in a direction to close the breaker, and a trip device carried on the carriage and operable in response to predetermined circuit conditions for operating the toggle to effeet disconnection of the operating member from the carriage.

13. In combination, a circuit breaker, power operated closing means for closing said breaker, means automatically operative to effect opening of said breaker, said circuit breaker remaining operatively related and under the control of said power operated closing means at all times, and manually operable closing means for closing said circuit breaker, said automatic means when operated causing opening of said circuit breaker irrespective of the position of said manually operable closing means.

14. In combination, a circuit breaker, compressed gas closing means for closing the breaker, means automatically operative to effect opening of said circuit breaker, means operated simultaneously with said automatic means for deenergizing the closing means, said circuit breaker remaining operatively associated with and under the control of said closing means at all times, and manually operable closing means for closing said circuit breaker, said automatic means when operated causing opening of said circuit breaker irrespective of the position of said manually operable closing means.

JAMES M. CUMMING. ALLAN W. HILL. 

